Quantum dots are semi-conductor nanoparticles made up of group II-VI elements or group III-V elements and with sizes ranging from several nanometers to tens of nanometers. Quantum confinement effect can be observed in quantum-dot materials. Specifically, the electrons and electron holes within a quantum dot material can be squeezed into a dimension that approaches a critical quantum measurement, which enables the original continuous energy band to become discrete energy levels, whereby the material can emit visible light in response to an external excitation. The emission peak of a quantum-dot material has a relatively small half width at half maximum, and the color of light emitted by the quantum-dot material can be tuned by changing the size, structure, and/or composition of the quantum dot. Therefore, use of a quantum-dot material in a liquid crystal display panel can effectively improve color saturation and extend color gamut of the liquid crystal display panel.
In view of the above-mentioned advantages of quantum dots, in the existing technologies, quantum dots are incorporated into a color filter of a liquid crystal display panel so as to improve the color performance of the display panel. However, in these display panels provided by the existing technologies, effects of quantum dots on the polarization state of light are ignored. Backlight or natural light becomes linearly polarized light after passing through a polarizer. When excited by said linearly polarized light, a quantum-dot material will emit elliptically polarized light rather than the original linearly polarized light. After passing through a polarization analyzer, said elliptically polarized light will have a distinctly reduced transmittance, thus enabling the display panel to fail to display normally.
Furthermore, in an existing liquid crystal display panel using quantum dots, the backlight source is usually a blue-light backlight source. In case of insufficient absorption of the blue backlight by a quantum-dot layer, a blue-light filtering layer is provided, which can greatly decrease the transmissivity of the display panel.
In addition, the existing liquid crystal display devices also fail to consider effects of an excitation from outside surroundings on a quantum-dot layer.
In view of the foregoing technical problems, the present disclosure aims to provide a liquid crystal display device capable of producing better color effect and having a relatively higher transmissivity.